thank You for Your measurements and sorry for the confusion. As I said I took the data from printed material by Linhof. It seems that we cannot trust in Linhof brochures anymore, shame, shame. So please tell Linhof that they have to correct their brochures.
I own two TK (2x3 and 4x5) and could not measure a TKs. Until today I did not even measure my cameras. But tonight I will because Your measurements made me curious. Maybe the data in the TK manual is also wrong.
Linhof has not had accurate measurements for a long time. It seems that they might be making them from prototypes or design drawngs.
But the problem is increased by definition.
Total extension vs total extension to the film plane, Width and height on the TK 45, when folded does or does not include the bellows (it overhangs the camera but does not on the 23). Weight with or without lensboard?
After all you do need a lens board.
In the US a lens board is included with the TK. In Germany it is not included.
I compared the TK and TKS side by side yesterday. The differences as previously stated were slight. The TKS was slightly more stable with a heavy back attatched, but this was very marginal. I liked them both, had a real dilema choosing which one, but finally opted for the TKS as I would never have been quite certain otherwise. Thank you for your comments and advice.
Robin
PS Could you tell me a bit about the Boss screen please?
"Could you tell me a bit about the Boss screen please"
The Boss screen uses a layer of paraffin sandwiched between 2 pieces of glass. That means that it must be made for a specific camera brand as the wax layer is the imaging forming layer, unlike a ground glass where the ground side is the imaging forming layer. On a Linhof the ground side of the ground glass sits on 4 small, adjustable shims which allow service to adjust the exact positioning of the focusing layer of the screen. On a Boss screen that layer need to be compenstaed for so the internal wax layer is exactly on the film plane.
So you must have a Linhof specific Boss screen and, since tolerances occur, a service center should verify proper placement by calibrating the shims.
This means that if you need to replace the screen in the field it may not be properly installed.
Additionally, since the image forming layer is wax, it has been reported that extremes in temperature for some people have caused the wax to melt and reset in summer (transportation of camera in unisulated case in car trunk). or freeze and reset (witer) which both result in the wax cracking.
In most cases, with the widest range of lenses (wide to long) best results frequently are with the latest version of the manufacturer's ground glass and fresnel combination.
bearing in mind that by adding an enhanced focusing screen, Boss, Super Screen, Beattie, etc. has not increased the volumn of light that enters the lens. So it needs to brighten by either concentrating the light reaching the eye (frequently at the cost of blacking out the image when the eye is not in the optical center) or by making the grain very fine which can result in short lenses becoming very difficult to focus as the image begins to appear as an aerial image. This also happens when the enhanced fresnel screen is the improper focal length for the lenses being used with the camera.
All of Bob's comments are correct. Having said that let me give you my real world experience with a BOSS screen on a Phillips 4x5 (the comments should transfer to a TKS but may not):
1) It is definitely brighter but I can't tell you how much. When I first got it I set up the Phillips and a Sinar side by side with same focal length lenses and compared .. not terribly scientific gut showed it was brigher.
2) Personally I find it easy to focus but not necessarily easier than focusing my otehr 4x5 field camera a Horseman 45FA. I do find that I hvae no trouble focusing f8 lenses with the BOSS screen. I have not experienced any lens blackout with it but have in years past with some of the other 'brighteners.'
3) The temperature extreme limitations should not be ignored. I if you are in South Florida or the LA Basin, for example, and leave yoru camera in a closed car for a few hours in temperatures over 100?F it will melt. Under normal high temperatures and with reasonable care there should be no problems. I hvae heard about the opposite extreme of cracks apeparing as a result of freezing but have not experienced any of it and I DO work in very cold temperatures. I have had the camera out in tempoeratures way below freezinfg for several hours with no ill effects.
4) The screen I am using is now pushing two years old and has suffered no ill effects from use. There is a slight separation at one corner (2mm square at the most) which I first noticed about nine months ago and it hsa not gotten any bigger and is outside the image area anyhow.
5) Since I never take both the Phillips and the Horseman (Horseman has standard GG w/fresnel) out together I can't compare the two. Thinking about it I don't believe the Phillips is REALLY any brighter than the Horseman but I tend to not use the slower lenses on the Horseman anyway.
Bottom line, a good screen. Ihvae used it for long enough to recommend it but I am not jumping up and down saying it is the be all and end all. The only real + in my mind is that I find fine focusing on the GG with a loupe somewhat more exact with the BOSS because it is so fine, again partially subjective. You won't be disappointed in it for srue.
Thanks for the information on the Boss screen. If I go for the Fresnel, is there a special (cornerless) one for the TK45S or is it the same as the one for the Master Technika ??
Posting Permissions
Reply With Quote
Bookmarks